Cinematographic projecting apparatus



Aug. 19, 1930. J. T. DOYLE 1,773,524

CINEMATOGRAPHIC PROJECTING APPARATUS Filed July 9, 192a FM. F105. F109.F192 F108. L] E] [J [J [J I VE TEW' Patented Aug. 19, 1930 UNITED STATESJAMES THOMAS DOYLE, OF DUBLIN, IRELAND CINEMATOGRAPHIC PROJECTINGAPPARATUS Application filed July 9, 1928, Serial No. 291,335, and inGreat Britain July 22, 1827.

The present invention relates to the projection of colour music fromcinematographic apparatus.

Colour music consists of rays of light of changing colour projected onto a suitable screen. The rate of change and the variation of colourconstitute the music.

Hitherto, in the projection of such coloured lights, it has been usualto arrange a number of separate sources with the appropriate colourfilters, in conjunction with a key board and switch mechanism whichenables the operator to project any combination of colours at will. Inthe present invention the colour and intensity of the light projected iscontrolled by a suitable film adapted to replace the ordinary film incinematographic apparatus.

Such an efiect may be produced by colcuring the actual film with theappropriate designs and colours and then running it through a projectingmachine in the ordinary way. The difficulties of reproduction of copiesof such films would be great. The

present invention renders a coloured film imneccssary. A colour filteror filters interposed between the source of light and the projectinglens are masked or unmasked by opaque or semi-opaque portions of themov- 80 ing film, according to the colour and intensity of the light itis desired to project.

The invention is more fully described with reference to the accompanyingdrawings:-

Figure 1 shows the general arrangement of the projection apparatus.

Figures 2 and 3 show colour screens for use according to the invention.

Figures 4, 5 and 6, show examples of the manner in which the opaqueportions of the films are arranged.

Figures 7 and 8 show the colour screen and film of a modifiedarrangement.

Reit'erring to the general arrangement of the apparatus shown in Figure1 a condensing lens 1 throws an intense beam of white light from the areor other source of light 2, on to the projecting lens and shuttermechanism 3. The special film, having suitably arranged opaque andtransparent sections is arranged nearer to the projection lens than isusual with ordinary films, which are ordinarily arranged in or about theposition 5. The film may be wound on or off spools or rolls 6 and 7 asin known apparatus. Be 5 tween the film and the projecting lens isarranged a colour filter or screen 8 containing colour filters for eachof the three primary colours, red, green and blue. These filters may bearranged as sectors in a circular disc (Figure 2) or any suitablemanner. The colour filters are so arranged relative to the opticalsystem of the projector that the light passing through any sectorcompletely fills the screen on which the light is ca projected i. e.,the portions of the beam overlap or coincide on the screen.

It is obvious that the combination of the three primary colours on thescreen will pro duce white light and that by the subtraction 79 of anyparticular coloured component by obscuring or masking a portion of oneor more of the filters, any shade or intensity of colour may beprojected on to the screen. The proportion and intensity of any of the pi- 7 mary colours present in the projected beam is controlled by theopaque, semi-opaque or transparent sections of the moving film.

Figure 5 shows an example of a portion of a film adaptedfor use withfilter screen con- 80 t aining three filters, one for each primarycolour, arranged as sectors of a circular disc. The opaque portions ofthe film also form sectors of the appropriate size. The action of thefilm is as previously described. The opaque sector 10 obscures a certainportion of the filter which it comes opposite, and this produces acorresponding change in the projected light. In the same way the smallersector 9 removes a certain proportion of a component of a differentcolour from the beam, causing a further change in the colour of thelight projected on to the receiving screen. 95

If a colour filter with vertically arranged panels as shown in Figure 3is used, the opaque and transparent sections of the film are. arrangedcorrespondingly, to obscure the requisite portion of each filter. A filmwith 1.11:;

requisite amount of light I V l film shown in Figure 6 is apthe fixed,tri-colour filter of this modification the opaque sectors subtendsimilar angles to the colour filters but are displaced radially as shownat 11 and 12 in order to allow the to pass through the f these "lherelativ l s, lacement or sectors will cnvnge from point to point alongthe film, so varying the composition of the light transmitted.

The tri-colour disc or filter screen may be replaced by a screen havingalternate opaque and transparent coloured sections 13 and 14 as shown inFigure 7. The moving film (Figure 8) has the opaque portions 15 whichobscure the colour filters, so arranged, relatively to the colourfilter, that the proportion of light required of each colour, istransmitted. it the opaque portion of the film maslts the whole of thatparticular colour filter whicl it controls, then that colour is absentfrom the projected beam. It the opaque portion of the film coincideswith the opaque section of the colour filter, then the whole o1 filteris in use. Hence, by adjusting the position of the opaque band on thei'ilui.

a o r. r i-o'fiight can beprojected. lhe other two colours arecontrolled in similar manner. The advantage of such an a "rangement isthat the opaque portions 0 f the tihn ot unrarylngr size. and to varythe colour of the light projected only the position of the opaqueportions relative to the colour filters need be changed.

declare that what I claim is 1. Apparatus for projecting light ofvarying colour comprising in combination a so rce oi white light, aprojecting lens colour ilters arranged between said light and said lens.said colour filters arranged as sectors of disc, flexible translucentfilm including opaque areas arranged as sectors of a circle paced corspondingly to tl propor tion 0t said colour filters it is desired tomask, and means to displace said film relatively to said colour filters.

2. Apparatus for projecting light of vary ing colour comprising incombination a source oi white light. a projecting lens, colour filtersarranged between said source of light and said lens, said colour filtersarranged as sectors of a disc. a fiexible translucent film ineludingopaque areas arranged as sectors of a disc subtending similar angles toApparatus for projecting light of vary ing colour comprising incombination a source cit white light, a propctmg lens, colour nltersarranged between said source of d said lens, opaque areas of substannild alternately with said colour a le translucent film in luding opaqt.sec ons or unrarying size,

spaced corresponun said colour t lers whi and means to displac saidcolour filters.

a2 Apparatus for projecting light of varying colour comprising incombination a source of light, projectiin ns, fixed uniplanar 5; tem ofcolour filters between said lens and said light, said colour filtersbeing all arranged within the field of said projecting lens, a flexibletranslucent film including opaque areas spaced c "responding to theportions of said "olour ers it is desired to -e said film relay to theproportion i it is desired to mask, d film relatively to bill i ask, andmeans to d 1 UV y to said colour filters.

5. Apparatus tor pro ecting light of varying colour comprising incombination a source of wl'iite light, a proj e ting lens. a fixedcoplanar ystem of colour ilters between said projecting lens and llight. one. at said colour i to light substan ally r to light substantly green at to light substantially blue, c i i, r s

being simultaneously within the field of said projecting lens, afiesible tr nslucent film including opaque areas spaced corresptmdinglyto the portions of i ur filters it is desired to mask, and me. iisplacesaid film relatively to said colour filters.

6. A method of projecting light to produce color ellects which cons 'nproducir a beam of white light, i obs the passage of li t 01 terentportions of said lie-inn, seiectivel modifying the amountof light ineach of said portions, and projectii ,2 the obstructed and modifiedparts of the beam in overlapping relation onto a screen.

o signed

